The '4 Minutes' singer - who raises biological children Lourdes and Rocco and adopted David and Mercy - hasn't ruled out expanding her family further by taking on the care of another disadvantaged youngster.

Asked if she would adopt again, she said: "Never say never."

The 51-year-old star also spoke about her charity work with her Raising Malawi foundation, saying it makes her feel complete.

She said: "I'm really proud of the work that I'm doing in Africa. I feel a tremendous sense of accomplishment in terms of my career and the work that I have done.

"I have four children now and I'd like to think I'm a good mother. I feel a great sense of satisfaction in all areas of my life."

Madonna moved back to New York from London after divorcing her husband, director Guy Ritchie, last year, and admits she misses some aspects of her life in the UK.

She said: "I miss being able to walk around the neighbourhood. It's more mellow, laid back and relaxed in London than it is in Manhattan."